Extruded wing protection system and device

ABSTRACT

Systems, devices, and methods for an extruded wing protection and control surface comprising: a channel proximate a leading edge of the control surface, a knuckle disposed about the channel, a leading void, a trailing void, and a separator dividing the leading void and the trailing void; and a plurality of notches disposed in the extruded control surface proximate the leading edge of the control surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/421,166, filed Nov. 11, 2016, the contents ofwhich are hereby incorporated by reference herein for all purposes.

TECHNICAL FIELD

Embodiments relate generally to unmanned aerial vehicles (UAVs), andmore particularly to vertical take-off and landing (VTOL) aerialvehicles.

BACKGROUND

Flight control surfaces may be constructed using a lay-up method inwhich an aluminum or steel mold is created, a foam core or removablebladder is inserted into the mold, and manual labor is needed to heatthe mold, take it apart, and clean it up for further use. Another optionis to use injection molding, in which the control surface is constructedin two parts and assembled together. Injection molding may result inthicker, and heavier, parts.

SUMMARY

An exemplary system embodiment may include: an extruded control surfaceincluding: a channel proximate a leading edge of the control surface, aknuckle disposed about the channel, a leading void, a trailing void, anda separator dividing the leading void and the trailing void; and aplurality of notches disposed in the extruded control surface proximatethe leading edge of the control surface. The system may further include:a plurality of clips, where each of the plurality of clips may includeat least one pin disposed proximate a base of the clip; where the atleast one pin of each clip may be received by the knuckle of the controlsurface via the channel, where the knuckle may deform to accept the pin,and where the control surface may pivot about each pin. The system mayfurther include: at least one cuff, where the at least one cuff mayreceive an end of the control surface in a first cavity of the cuff; asecond cavity disposed on a side distal from the first cavity; and aservo adapter, where the second cavity may be sized to receive the servoadapter for controlling the control surface.

In additional system embodiments, each clip of the plurality of clipsmay further include: a first leg having a first protrusion for insertioninto an indentation on a top surface of a wing. Each clip of theplurality of clips may further include: a second leg having a secondprotrusion for insertion into an indentation on a bottom surface of awing. Each pin may be disposed in a plane substantially perpendicular toa plane of the first leg. Each pin may be tapered, and a narrow end ofeach pin may be distal from the base. The leading void may be proximateto the knuckle. The trailing void may be proximate to a trailing edge ofthe control surface. The knuckle may include an opening facing towards abottom surface of the control surface. The control surface may be madefrom a UV resistant plastic or a polycarbonate-ABS (PC-ABS).

An exemplary method embodiment may include: extruding a control surface,where the extruded control surface includes a channel proximate aleading edge of the control surface, a knuckle disposed about thechannel, a leading void, a trailing void, and a separator dividing theleading void and the trailing void. The method may also include cuttingthe control surface at a set length; and milling a plurality of openingsinto the cut control surface proximate the leading edge of the controlsurface. In some method embodiments, the leading void may be proximatethe knuckle, the trailing void may be proximate a trailing edge of thecontrol surface, the separator may be narrower in width than an outsidewidth of the control surface, and the knuckle may have an opening facingtowards a bottom surface of the control surface.

Another exemplary method embodiment may include: attaching at least oneclip to a wing of a vertical take-off and landing (VTOL) unmanned aerialvehicle (UAV); attaching a cuff to an end of an extruded controlsurface; and attaching the extruded control surface to the at least oneclip proximate at least one notch in the leading edge of the controlsurface. The method may further include: attaching a servo connector tothe cuff, where the servo connector controls movement of the controlsurface.

BRIEF DESCRIPTION OF THE DRAWINGS

The components in the figures are not necessarily to scale, emphasisinstead being placed upon illustrating the principals of the invention.Like reference numerals designate corresponding parts throughout thedifferent views. Embodiments are illustrated by way of example and notlimitation in the figures of the accompanying drawings, in which:

FIG. 1A depicts a front view of an exemplary vertical take-off andlanding (VTOL) unmanned aerial vehicle (UAV);

FIG. 1B depicts a rear view of the exemplary VTOL UAV of FIG. 1A;

FIG. 1C depicts a top view of the exemplary VTOL UAV of FIG. 1A;

FIG. 1D depicts a perspective view of the exemplary VTOL UAV of FIG. 1A;

FIG. 2A depicts a top view of an exemplary control surface positionedapart from an exemplary wing of a VTOL UAV;

FIG. 2B depicts a cross-sectional view of the control surface of FIG. 2Awith an exemplary clip;

FIG. 2C depicts the control surface of FIG. 2B deflecting to insert apin of the exemplary clip;

FIG. 2D depicts a view of the control surface of FIG. 2B with the pin ofthe exemplary clip inserted into the channel in the exemplary clip;

FIGS. 3A-3C depict top views of the control surface, cuff, servoconnector, clip, and servo being connected to an exemplary VTOL UAV;

FIGS. 4A-4D depict top, side, close-up, and perspective views,respectively, of the exemplary control surface;

FIGS. 5A-5F depict top, side, cross-sectional, close-up, front, andperspective views of an exemplary clip;

FIGS. 6A-6G depict top, left side, cross-sectional, right side, front,front perspective, and rear perspective views, respectively, of anexemplary cuff;

FIG. 7 depicts an alternate exemplary clip for attaching an exemplarycontrol surface;

FIG. 8 depicts an exemplary wing protector for an exemplary VTOL UAV;

FIG. 9 depicts a flowchart of a method of producing an exemplaryextruded control surface;

FIG. 10 depicts a flowchart of a method of assembling an exemplary VTOLUAV;

FIG. 11 depicts a flowchart of a method of protecting a wing of anexemplary VTOL UAV from damage; and

FIG. 12 depicts a front view of the exemplary VTOL UAV of FIG. 1Alanding at an angle.

DETAILED DESCRIPTION

The present system allows for a flight control surface that may bemanufactured by the extrusion of material, such as a plastic, through adie. Embodiments disclose an extrusion process, used to create objectsof a fixed cross-sectional profile, for control surfaces where materialmay be pushed through a die of the desired cross-section. Extrusion ofmaterial may provide benefits of simplifying, speeding-up, and greatlyreducing the cost of manufacturing the control surface. By utilizing anextruded control surface with two voids and a separator dividing thevoids, the control surface may be light, having thin walls, andinexpensive to produce, while retaining structural integrity andstrength. Such structural integrity of different parts of a UAV allowthe overall structure to hold together under a load or impact, includingany weight exerted on the UAV, without breaking or deformingexcessively.

FIG. 1A depicts a front view of an exemplary vertical take-off andlanding (VTOL) unmanned aerial vehicle (UAV) 100. The VTOL UAV 100 maycomprise four pairs of rotor or propellers 102, 104 with the second setof propellers hidden behind the first pair of propellers 102, 104, asshown in FIG. 1C. Motors 106, 108 mounted in respective motor podstructures 110, 112 drive the propellers 102, 104. The VTOL UAV 100 alsoincludes a starboard wing 114 and a port wing 116 between the motor podstructures 110, 112 and a fuselage 118. Each wing 114, 116 may have aleading or first edge 120 and a trailing or second edge 124. A pair ofcontrol surfaces 126, 128 may be attached proximate the second edges 124of each wing 114, 116. Starboard landing gear 130 may be disposed on abottom edge of the motor pod structure 110 distal from the propeller102. Port landing gear 132 may be disposed on a bottom edge of the motorpod structure 112 distal from the propeller 104. Central landing gear134 may be disposed on a bottom edge of the fuselage 118 proximate avertical stabilizer 136. In some embodiments, the vertical stabilizer136 may act as landing gear to prevent tipping of the VTOL UAV 100.

In one embodiment, VTOL aerial vehicles may take-off vertically,transition from vertical flight to horizontal flight, and fly forwardhorizontally. Quadrotor aerial vehicles have four motors and fourpropellers that are all aligned vertically toward a longitudinal axis ofthe quadrotor. The size of the propellers in a quadrotor is significantrelative to the overall size of the quadrotor in order to provideappropriate control over the quadrotor and to reduce the power requiredto fly the quadrotor. The aerial vehicle may be controlled by anon-board control system that adjusts thrust to each of the motors andcontrol surfaces 126, 128. The on-board control system may include aprocessor having addressable memory and may apply differential thrust ofthe motors to apply both forces and torque to the aerial vehicle.Accordingly, the control surfaces 126, 128 may play an important role inproviding control of the UAV. Additionally, control surfaces producedusing an exemplary extrusion process may be able to reduce weight andcomplexity. In one embodiment, control surfaces 126, 128 may be trailingedge wing elevons. In other embodiments, the control surfaces 126, 128may optionally be rudders, elevators, flaps, ailerons, speed brakes,etc. A series of exemplary clips 138 may be spaced along the length ofthe wings 114, 116 to connect the wings 114, 116 to the control surfaces126, 128. In some embodiments, the clips 138 may be replaced with a moresubstantial connector, as shown in FIG. 7.

The fuselage 118 and motor pod structures 110, 112 may be made fromplastic, e.g., using an injection molding process. The wings 114, 116may be made from molded foam so as to minimize weight and maximizeflight time of the VTOL UAV 100. Injection molded wings would add asignificant weight to the VTOL UAV 100. In some UAV embodiments, themolded foam wings may form a live hinge where the foam is compressed.This live hinge is subject to breaking or be separated into pieces as aresult of a blow, shock, or strain. A piece of tape of other materialmay be applied over the live hinge to extend its use, but this does notsubstantially extend the use. Molded foam wings may be limited incross-section to about 3-5 mm in thickness, as compared to a thicknessof about 2 mm of the trailing edge in the disclosed control surface 126,128. Further, molded foam wings having a narrow cross section may needto be hand trimmed and may suffer from a very high rejection rate ascompared to the disclosed extruded plastic control surfaces 126, 128.

The molded foam wings 114, 116 may include a plurality of recesses toreceive the plurality of clips 138 for attaching the control surfaces126, 128 to the wings 114, 116. The molded foam wings 114, 116 may beespecially susceptible to damage from denting as compared to the plasticfuselage 118 and motor pod structures 110, 112. If the VTOL UAV 100 wereto land on an uneven surface or a surface with one or more obstacles,such as rocks, the foam wings 114, 116 could be dented. Denting of thefoam wings 114, 116 may cause a loss of efficiency or maneuverability ofthe VTOL UAV 100. In some embodiments, damage to the wings 114, 116 maynecessitate a repair or replacement of the wings. In one embodiment ofthe VTOL UAV 100, the control surfaces 126, 128 may be used asdisposable wing protectors. That is, since the VTOL UAV 100 may take-offand land in a vertical orientation, it makes the foam wings 114, 116susceptible to damage during take-off and landing. The control surfaces126, 128 may be positioned between the ground and the wings 114, 116 inorder to absorb any damage incurred during take-off and landing thatwould otherwise damage the foam wings 114, 116. Accordingly, by actingas a barrier between the foam wings 114, 116 and the ground, the controlsurfaces 114, 116 may provide a disposable extruded protection systemwhereby the extruded protection system may, upon sustaining any damage,be restored. The control surfaces 114, 116 may be easily replaced by auser at a minimal cost if damaged.

In one embodiment the control surfaces 126, 128 may be made from anextruded plastic. Additionally, in some embodiments, control surfaces126, 128 may be made from a UV resistant plastic so as not to degradeduring use of the VTOL UAV 100. In some embodiments, the controlsurfaces 126, 128 may be made from polycarbonate-ABS (PC-ABS). Thesecontrol surfaces 126, 128 may act to protect the wings 114, 116 fromdenting as the control surfaces 126, 128 are disposed between the easilydented foam wings 114, 116 and the ground during vertical landing of theVTOL UAV 100. If the VTOL UAV 100 were to land in an area with hardobjects such as, a rock, the control surface 126 may forcibly contactthe rock before the wing 114 impacts the rock, causing the controlsurface to deflect or absorb the impact, while preventing damage to thewing 114. As a result of an impact, the harder plastic surface of thecontrol surface 126 may be scratched or deflected, but not materiallydamaged. If the control surface 126 were damaged, it could be quicklyreplaced by a user at a lower cost and shorter time than replacing thefoam wing 114. In some embodiments, the control surface 126 may act as awing 114 protection system and device.

A pair of cuffs 140, 142 may be fit over an end of each control surface126, 128 proximate to the fuselage 118 of the VTOL UAV 100. The cuffs140, 142 may be fit to each control surface 126, 128 via a friction fit,snap-fit, and/or an adhesive. A first direct drive servo may be used toadjust control surface 128, as shown in FIG. 3A. A second direct driveservo may be used to adjust control surface 126, as shown in FIG. 1A.

FIG. 1B depicts a rear view of the exemplary VTOL UAV 100 of FIG. 1A.One or more sensors 144 may be disposed in the fuselage 118 of the VTOLUAV 100. FIG. 1C depicts a top view of the exemplary VTOL UAV 100 ofFIG. 1A. The VTOL UAV may include four propellers 102, 104, 146, 148separated by winglets 150, 152, 154, 156. Vertical stabilizers 136, 158may be used to prevent tip over of the VTOL UAV 100 upon landing. FIG.1D depicts a perspective view of the exemplary VTOL UAV 100 of FIG. 1A.After vertical take-off, the VTOL UAV 100 may transition to horizontalflight to cover a greater area, and then transition back to a verticalorientation for landing. The VTOL UAV 100 may use the propellers 102,104, 146, 148 and control surfaces 126, 128 to effect the transitionbetween vertical and horizontal flight.

FIG. 2A depicts a top view of an exemplary control surface 126positioned apart from an exemplary wing 114 of a VTOL UAV. The wing 114may include a plurality of clips 138 disposed about the wing. The clips138 may be attached in a recess in the wing 114. In some embodiments,the clips 138 may be secured to the wing via an adhesive.

The control surface 126 may include a plurality of notches 200 thatcorrespond to the placement of the plurality of clips 138, such that thenotches 200 may accept the clips 138 and allow rotation of the controlsurface 126 about the attachment point of the clips 138. The notches 200may be disposed in a leading edge 202 of the control surface 126 distalfrom a tapered trailing edge 204. The notches 200 include portionslaterally about both sides of the notches 200. A cavity structure orchannel 206 is defined at the leading edge 202 of the control surface126, running laterally along the entire length of the control surface126. The channel 206 is shaped and sized to receive a pin 208 extendingfrom either side of a base 209 of the clip 138 to allow the controlsurface 126 to rotate about the pin 208.

The control surface 126 has a constant cross-section along its lengthwhich results from the extrusion of the material, such as a plastic, inthe lateral direction of either X1 or X2, as shown in the cross-section2B. In one embodiment, at least one pin 208 of each clip may be receivedby the knuckle 210 of the control surface 126 via the channel 206, wherethe knuckle provides a bend or bows to accept the pin. Additionally, thecontrol surface 126 may pivot about each pin, thereby effecting amovement for providing control to the UAV.

FIG. 2B depicts a cross-sectional view of the control surface 126 ofFIG. 2A with an exemplary clip 138. The shape of the control surface 126cross-section is determined by the die, which the die was extrudedthrough at the time of manufacture. The cross-section, via the die,defines not only the exterior shape of the control surface, but also thechannel 206, a knuckle 210, a leading void 212, a trailing void 214, anda separator 216 dividing the leading void 212 and the trailing void 214.A thickness of the separator 216 may, for example, be about half athickness of an outer wall 218 of the control surface 126. The separator216 provides torsional strength to the control surface 126 and preventsthe voids 212, 214 from collapsing inward as the control surface 126 isextruded during an extrusion process. In some embodiments, the controlsurface 126 may include a plurality of separators. The voids 212, 214may be hollow in the form of two or more cavities, such as carveouts ortubes. In some embodiments, the voids 212, 214 may be filled with a foamor other material to add additional strength to the control surface 126.

A conduit such as a channel 206 may define the knuckle 210 allowing aleading edge portion 220 to deform 222 in the manner and direction shownby the arrow 224, so that the channel 206 may have the ability to expandto receive the pin 208 extending from the base 209 of the clip 138. Thematerial used for the control surface 126 and the shape of the knuckle210 and channel 206 provide the give needed to deform and return to itsoriginal shape. The knuckle 210 is sized to receive the pin 208 to allowfree rotation thereabout, while minimizing the play between the pin 208and the knuckle 210. The pin 208 may be inserted into the channel 206 ofthe knuckle 210 in the direction 224 shown in dashed arrow. The controlsurface 126 may be made of sufficiently flexible material to allowattachment and/or detachment of the control surface 126 at knucklepoints at separate times, easing the installation or removal of thecontrol surface 126.

FIG. 2C depicts the control surface 126 of FIG. 2B deflecting to insertthe pin 208 of the exemplary clip 138. The knuckle 210 deflects ordeforms in an outward direction 222 to allow the pin 208 of the clip 138to enter the channel 206.

FIG. 2D depicts a view of the control surface of FIG. 2B with the pin208 of the exemplary clip 138 inserted into the channel 206 of theexemplary clip. As the pin 208 enters a final position in the channel206 the knuckle 210 deforms 224 back to its original position in thedirection indicated by the arrow 224. The pin 208 of the clip 138 may besecured to the control surface 126 via a snap-fit. The control surface138 may be secured to the clip 138 by hand and without any screws,special tools, or specific knowledge. A user may replace the controlsurface 138 in the field if the control surface 138 is damaged orotherwise needs replacement. The clip 138 may be detached from thecontrol surface 126 following an opposite movement where the controlsurface 126 is moved up and away from the clip 138 causing the knuckle210 to deflect as the clip 138 is removed from the knuckle 210 in asnap-action. The knuckle may have sufficient resilience to preventaccidental removal, while still providing ease of installation orremoval by a user.

The knuckle 210 may be disposed proximate a leading edge of the controlsurface 126. In one embodiment, the knuckle 210 may have a crescentshape cross-section proximate a top side of the control surface 126,with the opening of the knuckle 210 oriented toward a bottom side of thecontrol surface 126. The leading edge portion 220 of the knuckle mayextend from the crescent shape cross section toward the bottom side ofthe control surface 126. The leading edge portion 220 may extend farenough from the crescent shape portion of the knuckle 210 to allow auser to manipulate the leading edge portion 220. By pushing the leadingedge portion 220 away from the leading void 212, the knuckle 210deforms, allowing the 208 of the clip 138 to be removed from the knuckle210. The user may be able to manipulate the leading edge portion 220 toallow easy insertion and/or removal of the pin 208 of the clip 138 fromthe knuckle 210 of the control surface 126.

FIGS. 3A-3C depict top views of the control surface 128, cuff 142, servoconnector 300, clip 138, and servo 302 being connected to an exemplaryVTOL UAV. The wing 116 may include a plurality of indentations 304 forreceiving a portion of a clip. The indentations may be shallow toprovide enough surface area for the clip to have a suitable bondingsurface on the foam of the wing. The control surface 128 may be fit intoa first cuff cavity 306, shown in dashed lines, in the cuff 142. Thecuff 142 may be fit over the control surface 128 via an interference fitto allow for quick removal of the control surface 128 from the cuff 142,such as if the control surface 128 is damaged by an obstacle in landingwhile protecting the wing 116. In some embodiments, an adhesive may beused in the first cuff cavity 306 to secure the cuff 142 to the controlsurface 128.

A servo connector 300 may extend out from the fuselage 118 of the VTOLUAV. The servo connector 300 may be received in a second cuff cavity 308disposed on a side distal from the first cuff cavity 306. The secondcuff cavity 308 may receive the servo connector via an interference fit.The servo connector 300 may be a split connector that may close uponbeing fit into the second cuff cavity 308 to ensure a secure fit betweenthe servo connector 300 and the cuff 142.

The servo 302 may be disposed in the fuselage 118. The servo 302 may bea direct drive servo to ensure longevity and prevent any damage togears, such as during a deflection of the control surface 128 uponencountering an obstacle during a landing of the VTOL UAV. Theinterference fit between the servo connector 300 and the cuff 142 alsoensures that control of the control surface 128 is maintained even ifthe wing 116 is partially separated from the fuselage 118, such as mayoccur if the VTOL UAV lands corner first causing forces to separate thewing 116 from the fuselage 118 to prevent damage to the foam wing 116.The control surface 128, clips 138, and cuff 142 may each be detachablyattached and replaced if desired by the user of the VTOL UAV.

FIGS. 4A-4D depict top, side, close-up, and perspective views,respectively, of the exemplary control surface 128.

FIGS. 5A-5F depict top, side, cross-sectional, close-up, front, andperspective views of an exemplary clip 138. Two pins 208 extend from abase 209 of the clip 138. The pins 208 may have tapered ends to aid inease of installation of the pins 208 in the control surface. The clip138 may have a top or first leg 500 and a bottom or second leg 502. Thefirst leg 500 may include a first protrusion 504 for insertion into anindentation on a top surface of a VTOL UAV wing, as shown in FIG. 3A.The second leg 502 may include a second protrusion 506 for insertioninto an indentation on a bottom surface of the VTOL UAV wing. In someembodiments, the first leg 500 and second leg 502 may be designed so asto prevent incorrect, or backward, installation of the clip 138, e.g.,via a non-symmetrical poka-yoke design that only allows the clip 138 tobe installed in one orientation.

FIGS. 6A-6G depict top, left side, cross-sectional, right side, front,front perspective, and rear perspective views, respectively, of anexemplary cuff 142. The cuff 142 may include a first side 600 disposedproximate a fuselage of the UAV when installed, and a second side 602distal from the first side 600 and proximate a control surface wheninstalled. The cuff 142 may include a plurality of cavities. The firstcavity 306 may be sized to receive the control surface, also shown inFIG. 3A. The second cavity 308 may be sized to receive the servoconnector, as shown in FIG. 3A. In some embodiments, the cuff 142 mayinclude additional cavities, such as a third cavity 604 to reduce weightof the cuff 142. The cuff may be created via injection molding and madefrom a plastic.

FIG. 7 depicts an alternate exemplary clip 700, 702 for attaching anexemplary control surface. The clip 700, 702 may extend across atrailing edge 704 of the wing 706 of the VTOL UAV 708. The greatersurface area of the clip 700, 702 may distribute the load and limitforces on the wing 706, which may cause denting of a foam wing. The clip700, 702 may be made from injection molding, such as an injection moldedplastic.

FIG. 8 depicts an exemplary wing protector 800, 802 for an exemplaryVTOL UAV 804. The wing protector 800, 802 may extend across a leadingedge 806 of the wing 808, 810. The foam wing 808, 810 may be especiallysusceptible to damage from user handling, e.g., the foam may formindentations from user fingers. The wing protector 800, 802 may beformed via extrusion via a die. In other embodiments, the wing protector800, 802 may be formed via injection molding. The wing 808, 810 of theVTOL UAV 804 has some twist in it, i.e., it is not perfectly straight.In embodiments where the wing protector 800, 802 is formed via extrusionthe wing protector 800, 802 may be processed to add a twist. In otherembodiments, the difference in the twist may not be significant enoughto require further processing.

FIG. 9 depicts a flowchart of a method 900 of producing an exemplaryextruded control surface. A control surface is extruded via a die (step902). A vacuum may be used to prevent the control surface fromcollapsing in on itself during the extruding process. The extrudedcontrol surface may include a knuckle, a channel, a leading void, atrailing void, and a separator dividing the leading void and thetrailing void. The control surface is cut to a set length (step 904).The set length may be a desired length of a control surface or wingprotector. A plurality of notches are milled into the control surfaceproximate the leading edge of the control surface (step 906). Thenotches may be milled via a computer numerical control (CNC) machine,e.g., a CNC router. The notches may be milled at set intervals to alignwith clips to attach the notches to a wing of a VTOL UAV.

FIG. 10 depicts a flowchart of a method 1000 of assembling an exemplaryVTOL UAV. At least one clip is attached to a wing of a VTOL UAV (step1002). At least one cuff is detachably attached to an end of a controlsurface (step 1004). At least one pin of the at least one clip isdetachably attached to the control surface via a channel of the controlsurface proximate at least one notch of the control surface (step 1006).In one embodiment, a servo connector is detachably attached to the cuffvia a cavity of the cuff (step 1008).

FIG. 11 depicts a flowchart of a method 1100 of protecting a wing of anexemplary VTOL UAV from sustaining damage. A user may attach a plasticcontrol surface, such as a plastic extruded control surface disclosedherein, proximate a trailing edge of a foam VTOL UAV wing (step 1102).The control surface may be disposed between the foam wing and the groundwhile the UAV is in a vertical orientation. The plastic extruded controlsurface may sustain damage during a take-off or landing of the VTOL UAV(step 1104). The control surface may impact any objects, e.g., rocks,uneven ground, obstacles, etc., during vertical flight prior toimpacting the foam wing. As a result, the control surface may sustaindamage and need replacement, but the wing may be protected and notneeded to be replaced or repaired. Damage to the plastic control surfacemay be identified (step 1106).

A user, operator, or a software system may provide notification that theplastic control surface has been damaged. For minor damage, such ascosmetic damage or light scratches, repair or replacement may not benecessary. For severe damage, such as cracks, punctures, bends, etc.,the control surface may need to be replaced. Absent the extruded plasticcontrol surface, damage to the control surface may otherwise have causeddamage to the foam wings. The damaged plastic control surface may beremoved (step 1108). A user may easily remove the extruded plasticcontrol surface disclosed herein via a snap-off action. The user maybend an edge of the knuckle to allow a pin of the clip to be removedfrom the channel of the control surface. A new plastic control surfacemay then be attached to replace the damaged plastic control surface(step 1110).

Due to the low cost, ease of identifying damage, ease of removal, andease of installation, the plastic control surface may be frequentlyreplaced while still keeping the operation of the VTOL UAV economical.In some embodiments, the plastic control surfaces may be replaced everyset number of flights to ensure that the control surfaces provideprotection to the foam wings.

FIG. 12 depicts a front view of the exemplary VTOL UAV 100 of FIG. 1Alanding at an angle. The UAV 100 may descend 1200 vertically toward theground 1202. The UAV 100 may not land in a vertical orientation due toan error, strong winds, etc. In such a case, the UAV 100 may firstcontact the ground 1202 at port landing gear 132. The impact between theport landing gear 132 and the ground 1202 may cause some separationbetween the port wing 116 and the fuselage 118 to prevent breaking,cracking, or tearing of the wing 116. The cuff 142 is fit to controlsurface 128. The cuff 142 may separate from the fuselage 118 and theservo connector extending from the fuselage, as shown in FIG. 3A. Sincethe servo connector fits into the second cuff cavity of the cuff 142, asshown in FIG. 3A, the servo may continue to adjust the orientation ofthe control surface 128 during the non-vertical impact as shown in FIG.12. This continued control could allow the UAV 100 to abort the landingwhile maintaining the maneuverability needed from its control surfaces126, 128, e.g., to maneuver the UAV vertically away from the ground 1202until the wind has subsided enough to allow for a near vertical landing.A fixed connection between a servo and a control surface could causedamage to the servo in the impact shown in FIG. 12, which would besignificantly more costly to replace than the control surface 128.

The ground 1202 may include one or more obstacles 1204, such as rocks.As the UAV 100 descends 1200, it may contact the obstacle 1204 in itslanding location. The control surface 126 may absorb the impact of theUAV 100 with the obstacle 1204 such that the control surface 126 isdamaged or destroyed, but the foam wing 114 is not damaged. The controlsurfaces 126, 128 are disposed at the trailing edge of the foam wings114, 116 and are positioned between the foam wings 114, 116 and theground 1202. It is easier and less expensive for a user to continuallyreplace the control surfaces 126, 128 than to repair or replace the foamwings 114, 116. Due to the vertical take-off and landing of the VTOL UAV1200, the UAV 100 is more likely to sustain damage to the trailing edgeof the foam wings 114, 116 than in a horizontal take-off UAV. Theplastic control surfaces 126, 128 provide protection for the morefragile wings 114, 116 without the need for heavier or more expensivedamage resistant wings.

It is contemplated that various combinations and/or sub-combinations ofthe specific features and aspects of the above embodiments may be madeand still fall within the scope of the invention. Accordingly, it shouldbe understood that various features and aspects of the disclosedembodiments may be combined with or substituted for one another in orderto form varying modes of the disclosed invention. Further, it isintended that the scope of the present invention is herein disclosed byway of examples and should not be limited by the particular disclosedembodiments described above.

1. A system comprising: an extruded control surface comprising: achannel proximate a leading edge of the control surface, a knuckledisposed about the channel, a leading void, a trailing void, and aseparator dividing the leading void and the trailing void, wherein theleading void is proximate to the knuckle; and a plurality of notchesdisposed in the extruded control surface proximate the leading edge ofthe control surface.
 2. The system of claim 1 further comprising: aplurality of clips, wherein each of the plurality of clips comprise atleast one pin disposed proximate a base of the clip; wherein the atleast one pin of each clip is received by the knuckle of the controlsurface via the channel, wherein the knuckle deforms to accept the pin,and wherein the control surface pivots about each pin.
 3. The system ofclaim 2 further comprising: at least one cuff, wherein the at least onecuff receives an end of the control surface in a first cavity of thecuff.
 4. The system of claim 3, wherein the at least one cuff furthercomprises: a second cavity disposed on a side distal from the firstcavity.
 5. The system of claim 4, further comprising: a servo adapter,wherein the second cavity is sized to receive the servo adapter forcontrolling the control surface.
 6. The system of claim 2, wherein eachclip of the plurality of clips further comprise: a first leg comprisinga first protrusion for insertion into an indentation on a top surface ofa wing.
 7. The system of claim 6, wherein each clip of the plurality ofclips further comprise: a second leg comprising a second protrusion forinsertion into an indentation on a bottom surface of a wing.
 8. Thesystem of claim 6, wherein each pin is disposed in a plane substantiallyperpendicular to a plane of the first leg.
 9. The system of claim 2,wherein each pin is tapered, and wherein a narrow end of each pin isdistal from the base.
 10. (canceled)
 11. The system of claim 10 whereinthe trailing void is proximate to a trailing edge of the controlsurface.
 12. The system of claim 1 wherein the knuckle comprises anopening facing towards a bottom surface of the control surface.
 13. Thesystem of claim 1 wherein the control surface is made from a UVresistant plastic.
 14. The system of claim 1 wherein the control surfaceis made from a polycarbonate-ABS (PC-ABS).
 15. A method comprising:extruding a control surface, wherein the extruded control surfacecomprises a channel proximate a leading edge of the control surface, aknuckle disposed about the channel, a leading void, a trailing void, anda separator dividing the leading void and the trailing void; cutting thecontrol surface at a set length; and milling a plurality of openingsinto the cut control surface proximate the leading edge of the controlsurface. 16-17. (canceled)
 18. The method of claim 1 wherein the leadingvoid is proximate the knuckle, the trailing void is proximate a trailingedge of the control surface, the separator is narrower in width than anoutside width of the control surface, and the knuckle comprises anopening facing towards a bottom surface of the control surface.
 19. Amethod comprising: attaching at least one clip to a wing of a verticaltake-off and landing (VTOL) unmanned aerial vehicle (UAV); attaching acuff to an end of an extruded control surface; and attaching theextruded control surface to the at least one clip proximate at least onenotch in the leading edge of the control surface.
 20. The method ofclaim 19 further comprising: attaching a servo connector to the cuff,wherein the servo connector controls movement of the control surface.